A micromechanical oscillating device is described in European Patent No. EP 1 212 650 B1. The micromechanical oscillating device includes an oscillating structure on a rectangular plate. The oscillating structure is connected to an elastic structure in the form of a torsion spring element via a connecting structure. This torsion spring element, in turn, is connected to a support structure for the micromechanical oscillating device. The connecting structure has a largely U-shaped design. It is used to convert external forces which act upon the torsion spring element in a largely perpendicular manner to a torsion axis at least partially to forces which act upon the torsion spring element parallel to the torsion axis.
In order to control micromechanical oscillating devices, in particular micromechanical oscillating mirrors, in a regulated manner, it is necessary to detect the current position of the micromechanical oscillating device.
When the micromechanical oscillating structure changes position, mechanical stresses, which may be piezoresistively converted into electric signals with the aid of resistors, form in areas in which a micromechanical oscillating structure is connected to the support structure. The position of the micromechanical oscillating structure may then be detected on the basis of these signals.
A piezoresistive system of this type is described in European Patent No. EP 1 944 596 A1. The rotating microelectromechanical system includes four resistors which are located at a 45° angle to each other relative to a torsion axis. When the micromechanical oscillating structure changes position, mechanical stresses, which are piezoresistively converted into electrical signals with the aid of the resistors, form in areas in which a micromechanical oscillating structure is connected to the support structure. The position of the micromechanical oscillating structure may then be detected on the basis of these signals.